Piston ring



T. E. M FALL Aug. 29, 1950 PISTON RING 5 Sheets-Sheet 1 Filed Nov. 12, 1946 \NVELNTOR OR EY5 1 THuRLow E. WF'Au. 1;; mwwmm Aug. 29, 1950 MQFALL 2,520,369

PISTON RING Filed Nov. 12, 1946 3 Sheets-Sheet 2 \NVENTOB THURLOW E. M FALL.

'UwM I Aug. 29, 1950 MCFALL 2,520,369

PISTON RING Filed Nov. 12, 1946 3 Sheets-Sheet 3 \NVENTOR mm aw kwsz wwm Patented Aug. 29, 1950 PISTON RING Thurlow E. McFall, Sparta, Mich; assignor to Muskegon Piston Ring Company, Muskegon, Mich., a corporation of Michigan Application November 12, 1946, Serial No. 709,330

7 Claims.

Thisinvention is directed to a novel structure of piston ring, and more particularly to a piston ring designed for use in the oil grooves of pistons, which is vented for the passage of oil and in which the ring is made of a plurality of sections located substantially end to end and of a generally arch shape, whereby, when the required number of the ring sections are used, a substantially circular ring is provided. The sections are mounted upon and held in substantially end to end relation to each other by a single length member of flat spring material which, when the rin is not in use and is out of a cylinder, holds the ring sections at their ends spaced a short distance apart, but such spring holding member may be altered with a resultant bringing of the ends of the ring sections more closely together, the spring opposite each ring section bearing against the bottom of the ring groove and being bent outward to provide a spring force which causes the sections, attheir outer bearin surfaces, to engage against the walls of a cylinder with the pressure required for removing and conserving lubricating oil in an internal combustion engine.

One object and purpose of the present invention is to make the oil rings of steel or other equivalent material which may be formed and shaped into ring sections of a channel form in cross section, and to provide the spring member in its length with properly positioned outwardly formed loops which partially extend between the adjacent ends of the flanges of said channel ring sections and with which webs of said ring sections are securely interconnected and normally made inseparable from the continuous spring band. Such sprin band is located at the inner sides of the ring sections, the flanges of which extend outwardly and at their outer edges are of an arc form, shaped in conformity with the cylindrical surface which they are to bear against. With a rin as thus constructed, the area of the flanges of the ring sections may be increased or diminished in accordance with the thickness or gauge of metal used without affecting the strength of the spring member which supplies the tension to the ring and upon the strength of which the unit pressure of the bearing surfaces against the wall of the cylinder is dependent. Therefore, a piston ring is provided which has characteristics of long life without undue unit pressure against the cylinder wall, the making of thering sections and of the spring to which they are connected are of separated and independent metallic parts permitting a design of each to conform to any specifications required in the matter of hearing area of the ring sections against the cylinder wall and the pressure with which they will be forced thereagainst.

A further object of the invention is to provide a piston ring which is economical to make, easily fabricated and assembled and readily installed for service.

An understanding of the invention may be had from the the followin description, taken in connection with the accompanying drawings, in which:

Fig. 1 is a horizontal section through a piston ring made in accordance with my invention on a plane between the opposed bearing flanges thereof.

Fig. 2 is a fragmentary section similar to Fig. 1, enlarged.

Fig. 3 is a fragmentary edge view of the ring.

Fig. 4 is a fragmentary inner elevation of the ring.

Fig. 5 is a fragmentary horizontal section through a piston having the ring installed in a groove thereon and located within a cylinder.

Fig. 6 is a fragmentary enlarged vertical section through the piston and cylinder at an oil groove therein, the ring of my invention being shown in transverse vertical section.

Fig. 7 is a View similar to Fig. 2 showing the spring formation slightly modified.

Fig. 8 is a view similar to Fig. 4 illustrating a modification in the construction of the spring member for oil venting or passage.

Fig. 9 is a view similar to Fig. '7 illustrating the ring made up of a greater number of ring sections, and,

Fig. 10 is a similar view showing a somewhat modified form for greater flexibility of the spring ring member in rings having a lesser number of sections.

Fig. 11 is a plan view, partl in section, of a modified form of piston ring.

Fig. 12 is a fragmentary section of the same with the ring parts expanded.

Fig. 13 shows the same parts as Fig. 12 with the ring members compressed as in the cylinder of an engine, and

Fig. 14 is an enlarged cross section on the line l4l4 of Fi 12.

Like reference characters refer to like parts in the different figures of the drawings.

In the construction of the ring, a plurality of segments of channel form and of substantially identical construction are used, which are shaped in the arc of acircle so that when all of them are located in an end to end relation, they substantially complete a circle. Each of the se ments made from flat metal has a vertical web I with outwardly extending upper and lower flanges 2. The web may have a number of oil passing openings 3, as shown in Fig. 3. The number of these sections which may be used in a ring is variable. For example, in Fig. 1, eight of said sections are shown but in Fig. 9, the lengths of the sections are reduced so that a greater number will be used in a completed ring.

The sections with adjacent ends spaced short distances apart are mounted and carried upon a spring member which is made from a single length of flat sprin metal. Said spring member comprises a plurality of straight sections 4 located one at the inner side of the web I of each of the ring sect-ions. The adjacent ends of the spring sections 2 are integrally connected by the re turn bends at each end of each section 4 which is again bent back to form a loop :5 preferably of the shape which is best shown in Figs. 1, 2 and 5. Each of the spring sections 4 like-wise may be vented, for example by cutting an elongated slot '7 between its opposite edges v(Fig. {1). The ends of the spring cometogether as at 8 in Fig. 1, the end portions of the spring being shaped ,to provide in effect a loop which is separated at its middle at 8.

The channel ring sections are disposed in succession around the spring member, one being mounted between the adjacent sides of successive loops 6 with the webs l of the ring sectionsseated in the U-shaped bends between the parts *5 ,and 6, with the side portions of the loops located-between the adjacent sides of the upper and lower flanges 2 at the ends of the adjacent sections. The width of the metal at the loops .26 may be reduced so that the straight sections 4 may be of a width approximating that of the axial dimension of the rin sections and for said loopsto-extend between the flanges 2. Such loops thus lo catcd serve as strut supports and reinforcements for the flanges insuring against.theirbeingbent toward each other, The yielding oi thespring material and itsflexibility permitsready: assembly -a cylinder, shown ate in Fig. 5, the spring is bent at each part t thereof by engagement against "the-bottom of the ring groove, the ends of the fiangesi of the sections being brought closer togeth'er. Such deformation of the spring results in the creation of forces within the spring and the outer edges of the flanges Zare pressed against the inner sides of the :cyl-inderuwallawith a pressure-in aecordancewith the-resistance of the spring against-the deformation. fiThesections t are bowed byengagement of zthe;--central.:

portions against the bottom ofthe ringigrooye in thepiston iii, and each rihg se'cfiolkis .pre'ssed outwardly and the edges of the-flanges .Ziorced against the cylinder wall. Gil.co1lected -from the cylinder :wall between the-uppeizand-lower;

flanges 2 can pass throughtheopeningsztaand I and be .drained to the interior of -the..-pist0n throngh the passages I l.

Lin-Figs? the structure is the sameaexcept the -sectionsl -of the spring member are initially iiri-"a 4 wardly bowed, as shown at M, resulting in a greater force generated in said parts 4a of the spring when installed in the groove of a piston and bowed in the other direction by contacting the bottom of the groove.

In Fig. 8, instead of oil venting slots 1 in the sections 4, upper and lower staggered notches 12 are made in the sections .4. It is to be understood that any provision of oil passing slots or notches in the sections 5 will result in lessening ,the spring tension, and therefore, that the force of the sprin may be readily controlled by the thickness of the metal used, and the dimensions of oil venting openings therein.

In Fig. 1G a modification is shown. The web I of each ring section is cut away midway between its ends to provide an opening I3, Midway between the ends of each spring section 4 a loop 6 with reverse U-shape bends 5 connecting it with the two parts of the section 4 is provided which is disposed inside its adjacent ring section opposite said opening. When the ring is installed, ,the loop 6 will be pressed outwardly and extend between the upper and lower flanges supporting them at their rniddles. Likewise, the flexibility of the spring is increased.

The ring structure described is of a very practical useful character. The gauge of metal used for the channel-like ring sections may be selected without reference to the thickness or other characteristics of the spring metal. Therefore the bearing area of ,the flanges 2 against a cylinder wall is subject .to variation without reference to spring material and any desired amount of pressure isobtainable. The spring is likewise not controlled as to its strength by the gauge of metal used for the ring sections which bear against the cylinder wall. This permits .a Wide latitude in the design .of rings as to'dim ensions of ,materials used, tension of .the rin when installed and unit pressures "of the bearingjsur- .faces againstthecylinder wall.

,As shown, and as a preferred structure, the spring is of a single lengthcf material. ,However, an equivalent spring structure may bepr'o- Yicled .by. .makir g .eachof the .polygonaljide's of ,a singlelength of material with outward return bends .at the ends to go around theends offthe webs of thering sections,,,and, clips substantially of the shapes of the loops hooked around theends of .saidbends, whereby theloops provided arenot integral with the polygonal ,sides of the sp'ring but are-provided partly at the ends'of said polygonal sides and partly-bytheclips .desc' bed. Therefore, the invention cemprehends ,a' sprmg structure whichmay begoadeofiseveral rts and, not necessarily of one single; length gfls'pr-ing material.

The above described structure ,is shown ,in Figs.,1;1,-1 e in which-20 represents-the polygonal ssides each beingreturn Jacinta-teach endatQZI iorming, sockets to receive; the .;e nds of the webs :Lof theringsections. The-olips gl a're :return ;-.bent.- at;.eachchd at 23 to hpokover the return :bentends 2 of, the sides 2! ilhe ilfIl JSIllJlOIliS defined the appended claims .and x515 to. be aconsidered comprehensive of ,all rfolfms'. ofv structurecom na ,r hin he r scon .1. .tA .zpiston.1:ing .-structure:, comprising, a. spring amembersof generally polygonal. ;f;orm .pf fiat thin .mater'iahhavingatat .ring 1 loops integral the loops beingiconncctedm, th .esides of-thepolygonal shaped -spring .b .u -.be nds .cpen, at .:t1 1 r inner sides, and a plurality of ring members, one being located at the outside of each of said sides of the polygonal spring member and each generally in the form of an arc of a circle, each of which at each end is seated in one of said bends to retain the ring sections in assembled connection with the spring member.

2. A structure as defined in claim 1, having oil passage openings through said ring sections and the sides of the spring member.

3. A structure as defined in claim 1, each of the sides of said spring member being spaced from its adjacent ring member at the middle portions thereof, whereby when pressed in a piston ring groove, said sides of the spring member are outwardly bowed.

4. In a piston ring, a plurality of ring sections of generally channel form having vertical webs and spaced outwardly extending flanges, said webs bein curved in the arc of a circle and having an openin therethrough and the edges of said flanges similarly curved, a spring member of flat metal of generally polygonal form having sides, one located at the inner side of the web of each ring section, and having loops at the ends of said sides of the ring member extending outwardly and passing between adjacent ends of the ring sections, said loops bein open at their inner sides and contractable, and interengaging portions on the loops and ring sections for securing them against separation, each of said sides of the spring member having an additional outwardly extending loop located in opposition to the opening through the web of its associated ring member.

5. In a piston ring, a plurality of ring sections, each includin a vertical web and a flange extendin outwardly from the web, said web being curved in the arc of a circle, a spring member of flat material of a generally polygonal form having a plurality of sides located one within the web of each of said ring members, and means formed with said spring at each of its corners extending outwardly between the ends of adjacent ring members and with which said ring members are interlocked at said adjacent ends thereof, each of said polygonal sides of the spring member being inset from the web of the associated ring member a distance sufficient that when the rin is installed in the groove of a piston, said polygonal sides are bowed outwardly and tensioned, the tension force generated therein serving to press said ring members outwardly, each of said sides of the polygonal ring member at an intermediate portion in the length thereof having a flexible portion, whereby when said sides of the polygonal spring members are bowed outwardly by engagement against the bottom of a ring groove, the resultant force of the distorted sides of the spring member is modified.

6. A piston ring structure comprising a plurality of ring members of channel shape, each having an inner web and outwardly extending upper and lower flanges, the outer edges of said flanges being are shaped, and a spring member made up of a plurality of separate sides in number equal to the number of ring sections, each of said spring side members being return bent at its ends and hooked over the respective ends of the web of a ring member, and means for connecting the adjacent ends of the respective spring side members.

7. The elements of claim 6 in which the means for connecting the ends of the spring side members comprises spring clips each having return bent ends hooked over and interlocking with the return bent ends of adjacent spring side members.

THURLOW E. McFALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,918,707 Mellor Jul 18, 1933 2,319,098 Zahodiakin May 11, 1948 2,355,772 Zahodiakin Aug. 15, 1944 2,439,546 McFall Apr. 13, 1948 

